As the American presidential melodrama unfolds, the formative culture of the two candidates becomes more and more evident.

It’s the senator vs. the promoter.

While the two candidates are close in age, and are now competing for the same office, they have long been formed in very different professional environments.

Go back to 1973. Joe Biden is a young senator — as young as is constitutionally possible, having been elected at age 29 but sworn in at age 30. He is the youngest man in a chamber organized by seniority. The other senator from Delaware, William Roth, is getting started on a 30-year run. The Democratic whip at the time is Robert Byrd of West Virginia, already 14 years a senator. Vice-president Biden would eulogize him in 2010 when Byrd died in office, having ensconced himself for 51 years.